Photosperes / Virtural reality editing in GIMP or other Libre Graphics?

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I have been wanting to play around with 360° photos for use with virtual reality glasses and maybe posting on social media that can handle the format. My Pixel cell phone allows me to create “photosperes” where you take a bunch of pictures, and it will stitch them together into a 360° view.

I’m wondering if there are any GIMP plugins, or other software that will remove the distortion from the picture and allow me to do touchups on it, then redistort it back to a 360° photo.

Here is an example of what one of these pictures looks like when you display it on a flat screen.

PANO_20180401_184132

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Hugin is usually the application for working with images that need lots of correction, such as this one. There are quite a few stitching errors in this images though, and they look like they’ll be pretty difficult to correct!

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Yes, that was stiched together with Google’s software on the Google phone.

I am not concerned with correcting the stitching, really. I am concerned with hypothetical pictures that I may take where I want to clone out skin blemishes, dodge/burn stuff, color correction, stuff like that.

Because I want to try 360° photography with a real 360° camera. I can borrow or rent a camera to try it out, but I want to make sure I can edit such pictures before going through that trouble or expense of acquiring the camera.

So the pictures off my phone are just “proof of concept” that I can edit a 360° picture, if I can find a way to undistort the picture, edit it on a flat screen, and then redistort it so it looks good in VR glasses.

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I own a Ricoh Theta 360 camera and I usually use Hugin for adjusting the orientation of photos, or Pan2VR for videos. Hugin exports to TIFF so you can finish it up in GIMP and even play around with the projection using gmic’s Deformation filters.

You should also take a look at @patdavid’s short tutorial on the subject: https://patdavid.net/2012/07/how-not-to-make-wee-planet-in-gimp/

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Using GIMP-2.10, Filters > Map > “Panorama Projection”. Add an alpha layer to the image before transforming. You can transform the image back and forth, to do that you need to remember the parameters, but they are conveniently stored as presets.

Using G’MIC, Deformations > “Equirectangular to nadir-zenith”, this allows you to easily reproject only the zenith and nadir.

Using Hugin (this is explained for Advanced/Expert mode), add an image, double-click on it to edit “image variables” > Lens > and set “degrees of view” as required (360 in this case, it should auto-detect that). Then open the “GL” fast panorama preview, in the Projection tab set the field of view to 90x90 and the projection to “Rectilinear”, adjust the field of view as needed using the scrollbars, pan around using the “Move/Drag” tab, then alt+tab back to the main window, in the “Stitcher” tab click on “Calculate optimal size”, don’t click on anything else, select only “Exposure corrected, low dynamic range” for an 8-bit image or only “High dynamic range” for a 32-bit image, and click “Stitch!”. Remember the exact field of view parameters, you will need them to transform the image back to an equirectangular image.

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32-bit images are stitched with ‘low dynamic range’ setting. ‘HDR output’ only invokes Hugin’s HDR merging application.

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My TIFF came out 8-bit and I was not given a choice of bit depth, nor do I see one in Hugin’s settings. Maybe it’s adaptive?

By the way, we’re not stitching in this example, only reprojecting.

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I usually choose TIFF under HDR output. I think LDR only does 8-bit TIFF. Maybe the confusion is between the optimizing step and the outputting one.

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output is of course the same as input, bit depth wise. but hugin’s tools work just as well with 32bit images as they do with 8bit images.

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Try “Filter->Map->Panorama Projection…” and here two links that explains how to use it:

And please use GIMP 2.10.2, because it was unusable slow in GIMP 2.10.0.

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